The current invention is a kit and method for the detection of bed bugs. The kit comprises at least one pair of polymerase chain reaction (“PCR”) amplification primers capable of forming a Cimicidae-DNA-amplification-product for a family of organisms of a Cimicidae. Additionally, the kit provides a specimen collection device for collecting a DNA sample from an area suspected of harboring one or more members of the Cimicidae family. The kit also provides a DNA probe having fluorescent primer chemistry. In a preferred embodiment, the nucleic acid amplification detection kit utilized a pair of PCR primers. The probe utilizes fluorescent primer chemistry and contains chemistry similar to commercially trademarked products, including: TAQMAN PROBES, MOLECULAR BEACONS, HYBRIDIZATION PROBES; OR ECLIPSE PROBES. Additionally, the kit contains a positive-control-Cimicidae DNA template for confirming Cimicidae-DNA-amplification-product.
Bed Bugs.
There are many species of insects that feed on warm-blooded animals. Bed bugs are small parasitic insects that prefer human blood. The name “bed bug” is derived from the insect's preferred habitat of houses and especially beds or other areas where people sleep. Bed bugs have been shown to hide in small nooks and crevices during the day, only appearing at night in order to feed on the sleeping human host.
Bed bugs are also known by a variety of names including wall louse, mahogany flat, crimson rambler, heavy dragoon, chinche and redcoat. Epidemiologists skilled in the art have shown that a number of human health effects may occur due to bed bugs including skin rashes, emotional responses, allergic reactions and infections. A current diagnosis of bed bugs involves both finding bed bugs and the occurrence of compatible symptoms.
Although not wanting to be bound by theory, the bed bug known as Cimex lectularius is the species best adapted to human environments. It is found in temperate climates throughout the world. C. lectularius may have originated in the Middle East, in caves inhabited by bats and humans. Other species include Cimex hemipterus, found in tropical regions, which also infests poultry and bats, and Leptocimex boueti, found in the tropics of West Africa and South America, which infests bats and humans. Cimex pilosellus and Cimex pipistrella primarily infest bats, while Haematosiphon inodora, a species of North America, primarily infests poultry.
Bed bugs were mentioned in literature of ancient Greece as early as 400 BC, and mentioned specifically by Aristotle. Pliny's Natural History, first published circa 77 AD in Rome, claimed bed bugs had medicinal value in treating ailments such as snakebites and ear infections. The belief in the medicinal use of bed bugs persisted until at least the 18th century, when Guettard recommended their use in the treatment of hysteria. Bed bugs were first mentioned in Germany around the 11 th century, in France in the 13th century and in England in 1583, though they remained rare in England until 1670. Some in the 18th century believed bed bugs had been brought to London with supplies of wood to rebuild the city after the Great Fire of London (1666). Giovanni Antonio Scopoli noted their presence in Carniola (roughly equivalent to present-day Slovenia) in the 18th century.
Although bed bugs have been known as human parasites for thousands of years, bed bugs were largely eradicated as pests in the early 1940's in most of the developed world due to the use of DDT. In contrast, the prevalence of bed bug bites and related conditions has been increasing since about 1995. Several reasons have been postulated, but none have been proven, for example:
Increased foreign travel;
Increased purchases of second-hand furnishings;
Increased focus on controlling other pests;
Neglecting bed bug countermeasures; and
Increased resistance of bed bugs to pesticides.
In general, bug bites can be embarrassing and uncomfortable, however, the bigger danger comes from bed bugs harboring diseases that may be transmitted during an infestation. It is well known that other types of bug bites cause very serious diseases. For example, Yersinia pestis is a type of bacteria that causes the Bubonic plague throughout certain parts of the world. Plague transmission from infected animals generally occurs in one of three ways: (i) bites from infected rodent fleas; (ii) direct contact with infected tissue or bodily fluids; (iii) inhaling infected flea fecal droplets. Bites from infected fleas accounts for about 85 percent of the human cases of bubonic plague transmission.
Bites from bed bugs from the Cimicosis family may lead to a range of skin manifestations from no visible effects to prominent blisters. Diagnosis involves both finding bed bugs and the occurrence of compatible symptoms. Treatment involves the elimination of the insect. Bed bugs can cause a number of health effects including skin rashes, psychological effects and allergic symptoms, additionally, bed bugs can be infected by at least 28 human pathogens. No study has found clearly that the bed bug insect bites are capable of transmitting a pathogen directly to a human being. Because bed bugs have been found with Methicillin-Resistant Staphylococcus Aureus (“MRSA”) and with vancomycin-resistant Enterococcus faecium (“VRE”), there is still fear that such pathogens can be transmitted to humans. If a connection between bed bug bites and human pathogen transmission is firmly established, such infected bed bugs could spread the drug-resistant bacteria to the community at large.
Adult bed bugs are reddish-brown, flattened, oval and wingless. Bed bugs have microscopic hairs that give them a banded appearance. Adults grow to 4-5 mm in length and 1.5-3.0 mm wide and can be seen with the naked eye. Newly hatched nymphs are translucent, lighter in color and become browner as they molt and reach maturity. Bed bugs may be mistaken for other insects such as booklice and carpet beetles, or vice-versa, which is one reason to correctly identify a bed bug infestation. Bed bugs are nocturnal and difficult to visually detect during the day.
Common Locations of Bed Bug Infestations.
The thin and flat nature of bed bugs bodies allow them to hide in cracks and crevices. They often will congregate in locations within a dwelling that are shielded from sunlight, including but not limited to the seams and inside cushioning of mattresses and chairs, supporting frames for beds, and baseboards. Although bed bugs can hide individually, they are social creatures and more often will congregate in groups.
Size of Bed Bug Infestations.
Some pest control professionals have deemed light infestations to be anything below 200 bed bugs in a residence; a medium infestation can be in the range of 200-300 bed bugs in a residence; and severe infestations can be as bad as 2,000-3,000 bed bugs in a single residence. With the recent reemergence of bed bugs in the developed world, hotels and other establishments that provide short-term lodging are at constant risk of infestations. This is especially concerning when bed bugs can be transferred from an infested residence or hotel room through suitcases.
Detection of Bed Bug Infestations.
The current detection methods for bed bugs are visual. For example, a diagnosis of bed bugs is confirmed typically by catching one and identifying it correctly together with symptoms of human bite marks. An indirect method of identification is black tracks on bedding, which are the bed bugs' fecal stains. (The stains show up best on white- or light-colored bedding, and may be more difficult to see on darker bedding.) When crushing kills a recently fed bed bug, the result is a blood smear on whatever surface they were crushed. Crushing them also will produce a unique sickly sweet scent, which can also be detected when a dwelling is severely infested.
Bed bugs can also be detected by their unique bite pattern of a linear group of three, sometimes referred to as a “breakfast, lunch, and dinner” pattern. Red welts can appear on the skin of people after a bed bug has fed. Bed bugs have an anesthetic in their saliva so the victim does not feel the bite when it feeds. In contrast, an allergic reaction can take place leaving an itchy welt when the victim wakes up in the morning. Some people do not have an immune response to bed bugs, showing no welts post-feeding. The effects of these bites on humans varies from person to person, but often produce welts and swelling that are more itchy and longer-lasting than mosquito bites. Some people, however, have little or no reaction. If an individual is awake in the middle of the night, a flashlight can be run up and down a mattress or bedding to attempt to locate active bugs. Some experts have suggested this technique because the physical vibrations of getting up from the mattress and turning on a room light may give bed bugs sufficient time to retreat to hiding places, making detection more difficult.
The surest sign of bed bugs is to see or capture an actual bed bug. Bed bugs tend to hide close to beds, and in tufts, seams and crevices in mattresses and bed frames. They may also hide in surrounding furniture, in piles of books or papers, in carpeting, in linens, in electrical outlets or under peeling wallpaper. Visual inspection of these areas can uncover bed bugs if present. Adult bed bugs look like apple seeds: they have flat copper-colored bodies and are about ¼ inch in length. When a bed bug feeds, its body swells and becomes bright red. Young bed bugs are very small, approximately 1/16 inch in length. Although Bed bugs can live for up to a year and can survive months without feeding, they normally try to feed every five to ten days.
Several more sophisticated methods for monitoring and detecting bed bugs have been used in the past. For example, U.S. Pat. No. 7,591,099, titled “Bed Bug Monitor,” issued to Lang, et al., on Sep. 22, 2009 describes an insect monitoring and trapping device that includes a base and a lid for covering the base, and is constructed to provide a trap interior and an insect opening for insects to access the trap interior. The device includes a heating device provided within the trap interior for attracting insects, and an adhesive surface provided within the trap for trapping insects. The entire content of this U.S. patent is hereby incorporated by reference.
U.S. Pat. No. 7,743,552, titled “Bed bug Detection, Monitoring and Control Techniques,” issued to Borth, et al., on Jun. 29, 2010 and describes one non-limiting variation of a detection arrangement includes one or more sensors each structured to detect at least one biochemical substance indicative of biochemistry of one or more target insect species and provide a corresponding sensor signal, a controller responsive to the sensor signal of each of the one or more sensors to determine if the one or more insect species are present and generate a corresponding output signal, and an indicator responsive to the output signal to indicate the presence of the one or more insect species. The entire content of this U.S. patent is hereby incorporated by reference.
Eradication of Bed Bugs.
Once a bed bug infestation is detected in a home or hotel, swift treatment of the problem is advised to help prevent the problem from spreading to different rooms or units in a building. Female bed bugs can lay more than 200 eggs in their lifetime; they can live for weeks to months without feeding. Moreover, bed bugs can travel more than 100 feet on their own, spreading from room to room on clothing, luggage and bedding. Early detection of an infestation is believed to be a key component to controlling it.
Commercial insecticides (usually pyrethroids) are applied as spot treatments to cracks and crevices where bed bugs are hiding. Increased penetration of the insecticide into cracks and crevices can be achieved if accumulated dirt and debris are first removed using a vacuum cleaner. Many readily available aerosol pesticide sprays will cause bed bugs to scatter making eradication more difficult. Dust formulations may be used to treat wall voids and attics. Repeat insecticide applications are recommended/required if bed bugs are present two weeks after the initial treatment, as it is difficult to find all hiding places and hidden eggs may have hatched
Eradication of bed bugs frequently requires a combination of pesticide and non-pesticide approaches. Pesticides that have historically been effective include: pyrethroids, dichlorvos and malathion. Resistance to pesticides has increased significantly over time and there are concerns of negative health effects from their continued use. Mechanical approaches such as vacuuming the insects and heat-treating or wrapping mattresses have been recommended.
The carbamate insecticide propoxur is highly toxic to bed bugs. However, in the United States the Environmental Protection Agency (EPA) has been reluctant to approve indoor use because of its potential toxicity to children after chronic exposure. Bed bugs are developing resistance to various pesticides including DDT and organophosphates. Some populations have developed a resistance to pyrethroid insecticides. Now often ineffective, the resistance to pyrethroids allows for new chemicals that work in different ways to be investigated, thus chemical management can continue to be one aspect to resolving bed bug infestations. There is growing interest in both synthetic pyrethroid and the pyrrole insecticide, chlorfenapyr. Insect growth regulators, such as hydroprene (Gentrol), are also sometimes used.
Bed bug populations in Arkansas have been found to be highly resistant to DDT, with an LD50 of more than 100,000 ppm. Studies conducted in Africa showed that DDT made bed bugs more active. Bed bug pesticide-resistance appears to be increasing dramatically. Bed bug populations sampled across the U.S. showed a tolerance for pyrethroids several thousands of times greater than laboratory bed bugs. New York City bed bugs have been found to be 264 times more resistant to deltamethrin than Florida bed bugs due to nerve cell gene mutation.
A population genetics study of bed bugs in the United States, Canada, and Australia using a mitochondrial DNA marker found high levels of genetic variation. This suggests the studied bed bug populations did not undergo a genetic bottleneck as one would expect due to insecticide control during the 1940s and 1950s, but instead, that populations may have been maintained on other hosts such as birds and bats. In contrast to the high amount of genetic variation observed with the mitochondrial DNA marker, no genetic variation in a nuclear RNA marker was observed. This suggests increased gene flow of previously isolated bed bug populations, and given the absence of barriers to gene flow, the spread of insecticide resistance may be rapid.
Traditional methods of repelling and/or killing bed bugs include the use of plants, fungi, and insects (or their extracts), such as black pepper, black cohosh (Actaea racemosa), Pseudarthria hookeri, Laggera alata, Eucalyptus saligna oil, henna (Lawsonia inermis or camphire), “infused oil of Melolontha vulgaris” (presumably cockchafer), fly agaric (Amanita muscaria), Actaea spp. (e.g. black cohosh), tobacco, “heated oil of Terebinthina” (i.e. true turpentine), wild mint (Mentha arvensis), narrow-leaved pepperwort (Lepidium ruderale), Myrica spp. (e.g. bayberry), Robert geranium (Geranium robertianum), bugbane (Cimicifuga spp.), “herb and seeds of Cannabis”, “opulus” berries (possibly maple or European cranberrybush), masked hunter bugs (Reduvius personatus), “and many others.” In the mid-19th century, smoke from peat fires was recommended.
Silt-sized material-dusts have been used to ward off insects from grain storage for centuries, including “plant ash, lime, dolomite, certain types of soil, and diatomaceous earth (DE) or Kieselguhr”. Of these, diatomaceous earth in particular has seen a revival as a nontoxic (i.e. in amorphous form) residual pesticide for bed bug abatement. Insects exposed to diatomaceous earth may take several days to die.
Basket-work panels were put around beds and shaken out in the morning, in the UK and in France in the 19th century. Scattering leaves of plants with microscopic hooked hairs around a bed at night, then sweeping them up in the morning and burning them, was a technique reportedly used in southern Rhodesia and in the Balkans. Prior to the mid-twentieth century, bed bugs were very common. According to a report by the UK Ministry of Health, in 1933 there were many areas where all the houses had some degree of bed bug infestation.” Bed bugs were a serious problem during World War II. General MacArthur commented that bed bugs are the “greatest nuisance insect problem . . . at bases in the U.S.”
With the arrival of potent pesticides, famously DDT in the 1940s, bed bugs almost disappeared in western countries. Recently, bed bug infestations have resurged for reasons that are not clear, but contributing factors may be complacency, increased resistance, bans on pesticides and increased international travel. The current wave of bed bug infestations across America has spawned an industry for bed bug prevention, eradication, detection and reporting of infestations.
One skilled in the art appreciates that the bed bug detection kit and method used thereof can be a lower cost, and more effective alternative to early detection of bed bugs when compared to many other current methods used today. Additionally, the skilled artisan understands that many types of modifications can be made to the method without departing from the scope and spirit of the invention.